A 1200-kg station wagon is moving along a straight highway at 12.0 m/s. Another

Question

A 1200-kg station wagon is moving along a straight highway at 12.0 m/s. Another car, with mass 1800 kg and speed 20.0 ,m/s has its center of mass 40.0 m ahead of the center of mass of the station wagon (Figure 1) .

https://session.masteringphysics.com/problemAsset/1260308/3/YF-08-039.jpg

A)Find the position of the center of mass of the system consisting of the two automobiles.

B)Find the magnitude of the total momentum of the system from the above data.

C)Find the speed of the center of mass of the system.

D)Find the total momentum of the system, using the speed of the center of mass.

E)Compare your result of part D with that of part B.

Explanation / Answer

A)

x1 = Position of 1200 kg car = 0

x2 = Position of 1800 kg car = 40 m

m1 = 1200 kg , m2 = 1800 kg

Position of center of mass is given as

x = (m1 x1 + m2 x2) / (m1 + m2) = (1200 x 0 + 1800 x 40) /(3000) = 24 m

B)

Total momentum = m1 v1 + m2 v2 = 1200 x 12 + 1800 x 20 = 50400 kgm/s

c)

v = m1 v1 + m2 v2 /(m1 + m2) = 50400/3000 = 16.8 m/s

d)

Total momentum = (m1 + m2) v = 3000 x 16.8 = 50400

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.